Sediments and sedimentary history of Lake Attersee (Salzkammergut, Austria)

Abstract

Attersee represents a good example of a lake situated in the Northern forelands of the Northern Calcareous Alps and influenced by different sediment-supplying processes during the postglacial . Several compounds, of different origin, form the sediments of the basin . Clastics which are mainly composed of dolomites derive from the Northern Calcareous Alps . Clastic input of organic and inorganic particles is accomplished by rivers and landslides . They are responsible for the main input of siliciclasts like quartz, feldspar and mica . A high proportion of the sediment results from autochthonous biogenic carbonate precipitation . In the shallow sublittoral areas of the northern part of the lake benthic decalcification caused by encrusting macroand micro-phytes is dominant, while in the southern and central parts of the lake epilimnetic decalcification caused by the blooming of phytoplancton is more important during summer . The total biogenic calcium carbonate production reaches about 11000 to 12000 metric tons a year.Nutrients and residues of cyanophytes (Oscillatoria rubescens) deriving from the eutrophic lake Mondsee were washed into lake Attersee by the Mondseeache . High amount of phosphorus in the sediments of the southern basin depicts local eutrophication in the mouth area of the Mondseeache . The average sedimentation rate in lake Attersee can be determined by different dating methods . Sedimentation rates increased during the last 110 years from 1 mm a year to 1 .8-2 mm a year as a result of human activities . Five main phases in the postglacial sedimentary history can be recognized : Wurm moraines and finely banded varves (before 13 000 B .P.), the early Attersee stage (from 13 000 B.P. up to 1200 B .P.), and the later Attersee stage after the Bavarian colonization (from 1200 B .P. on) . Using heavy metal and isotope analyses the sedimentary history can be reconstructed in more detail for the last 100 years .

Intra-lake response of Arcellinida (testate lobose amoebae) to gold mining-derived arsenic contamination in northern Canada: Implications for environmental monitoring

“…The abundance of C. tricuspis has been linked with organic rich substrates and eutrophic conditions (Collins et al, 1990;Patterson et al, 2013). Several studies have suggested a link between elevated Ca concentrations and enhanced lake productivity (Otsuki & Wetzel, 1974;Kelts & Ksü, 1978;Behbehani et al, 1986). Therefore, the increase in C. tricuspis coupled and with a general increase in the faunal diversity and numbers of healthy lake-indicating taxa in HC may be indicative of enhanced lake productivity in the southern part of the lake.…”

High-resolution palaeohydrological reconstruction of central Italy during the Holocene

“…Two main explanations are possible: (a) the shells were dissolved after deposition and (b) the ion concentration in the lake water was strongly diluted because of enhanced runoff from the Lake Trasimeno catchment where limestones are absent. Examples of shell decalcification because of high lake productivity are reported at Lake Lansing, MI, US, (McNabb, 1979), Lake Attersee, Austria (Behbehan et al, 1986), at the Eifel maar lakes, Germany (Scharf, 1993), and at Preola and Gorgo Basso lakes, Sicily (Curry et al, 2016). The last authors suggest that shell dissolution could be because of both low Ca 2 + water concentration and to elevated levels of dissolved CO 2 as a result of increased primary productivity and organic matter decomposition.…”